Question
I see you replied to this subject on a house plant size mimosa.  I have two quite large trees.  One, about 5 feet and bushy, has a lot of scale.  Rounded type with black on them.  I brushed off as many as I could find.  Is there an insecticide to spray the tree with?  Alcohol and a qtip is a bit much for the sizes of my trees.  The other one being about 12 feet tall.

Answer
The easy thing to do is treat the tree with an insecticide called Bayer Advanced Tree and Shrub Insect Control. This is applied to the soil around the tree and the roots will transport the insecticide to the leaves and branches and when the scale insect sucks the plant juices they are killed. This will prevent infestations for the growing season. Here is a web link to this product. Check with your local garden type store for this product.
http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...